An automatic analyzer performs qualitative/quantitative analysis by adding a reagent specifically reacting to a specific ingredient contained in a living body specimen (hereinafter, referred to as a specimen) such as blood or urine, by causing the reagent to react therewith, and by measuring optical density or an emitted light quantity of reaction liquid.
According to this automatic analyzer, in order to cause the specimen and the reagent to react with each other, it is necessary to provide a step of dispensing the specimen which is an analysis target contained in a specimen container or the reagent which is added to and reacted with the specimen, into a reaction container. A small amount of the specimen or the reagent is dispensed into the reaction container. Accordingly, accurate dispensing inevitably affects accurate analysis. Therefore, it is important to reliably detect abnormal dispensing which may lead to inaccurate dispensing.
For example, as a technique of detecting abnormal dispensing, PTL 1 (JP-A-2008-224691) discloses a probe that aspirates and discharges a sample, at least one pressure sensor that detects pressure inside a dispensing channel connecting a dispensing syringe which generates pressure for aspirating the sample from and discharging the sample to the probe, pressure value storage means for storing an output value of the pressure sensor during a dispensing operation of the sample as a time-series, storage means for storing a reference database having a time-series output value of the pressure sensor when the probe normally aspirates or discharges the sample, and an automatic analyzer that calculates a Mahalanobis distance from comparison data created based on the output value of the pressure sensor which is stored as a time-series by the pressure value storage means, and the reference database, and that determines abnormal dispensing of the sample by comparing the calculation result with a predetermined threshold value.